Disclosed herein is a phase change ink suitable for printing on ophthalmic lenses. Ophthalmic lenses have been produced as semi-finished lens by bulk lens manufacturers and then distributed to individual laboratories to prepare the finished lens. Traditionally, label information for each semi-finished lens was provided by printing the relevant information on a paper envelop for each lens.
Recently, lenses have been labeled by using a phase change ink to print the relevant information directly onto the lens using a digital printer. However, current known phase change ink can exhibit performance issues for lens labeling applications including clogging of printer heads. Further performance issues include the need for jetting reliability, durability of the printed image on the lens, the need for printed images that are removable from the lens when no longer needed thereon, and the need for printed images on the lens that are of good print quality. Further, inks which require use of organic solvent in optical laboratories for removing or cleaning of the ink on lens can be problematic.
A need remains for an improved phase change ink suitable for printing on ophthalmic lenses. Further, a need remains for an improved phase change ink suitable for printing on ophthalmic lenses which have improved jetting reliability, improved durability after printing on lenses, provide printed images which are easy to clean and provide good adhesion on both hydrophilic and hydrophobic lenses, and which provide good optical contrast on both clear and dark lenses. Further, a need remains for an improved phase change ink suitable for printing on ophthalmic lenses wherein the printed images can be removed with water.
Throughout this application, various publications, patents, and published patent applications are referred to by an identifying citation. The disclosures of the publications, patents, and published patent applications referenced in this application are hereby incorporated by reference into the present disclosure to more fully describe the state of the art to which this invention pertains.